1 . Field of the Invention
The invention relates generally to the field of digital signal communications and channel allocation. More particularly, the invention relates to dynamically aggregating communications streams between two communicating terminals to accommodate variations in bandwidth requirements.
2. Description of the Related Art
In data communications systems that share communications channels, a procedure must be implemented to allow different users to take turns using the channels. However, different users may require differing amounts of data throughput at different times. For users that produce varying traffic patterns in the information network, it is desired to provide the required amount of bandwidth on-demand. Given that multiple users in the network may be contending for limited resources and may have different bandwidth needs, an optimal system will maximize throughput and minimize latency for individual users, while maximizing the efficiency of utilizing total system bandwidth and other network resources.
In many systems, users are allocated a channel for a limited period of time. Then the channel is de-allocated and allocated to another user. This is known as a circuit-switched system. In circuit-switched systems extensive setup must be done so that subsequent packets do not need to carry the full routing information. The packets instead will always travel the same circuit until that circuit is switched. Many circuit-switched systems provide a dedicated line or virtual line to every user. The bandwidth of this line varies depending on the desired value selected when a connection is established, but it remains constant for the duration of the connection. As a result, much of the dedicated bandwidth is unused for users with varying data traffic patterns.
In other systems, channels are never allocated but are always shared. This kind of system requires no overhead signaling for channel allocation and de-allocation but must have some way of directing packets and of resolving conflicts. Such systems are typically called packet-switched because each packet contains the full routing information required to direct the packet to its intended destination. Packet switching requires no overhead in the setup but adds significant overhead to each packet. For example, TCP/IP network users share the same high-bandwidth channel (i.e. wire), and each user takes more or less of the available shared bandwidth, depending on its needs and the bandwidth use of other users on the network. This enables dynamic, efficient bandwidth allocation both among users and for a single user as the data traffic pattern varies. However, this packet-based approach requires complete switching and addressing information with every packet, reducing bandwidth efficiency.